I get that you're not worried about money, but even beyond the principle, consider the time and ick factor. It's not about punishing him for his behavior. We're talking natural consequences-drunk or not, if you destroy someone's furniture, you should probably offer to fix the problem. Unfortunately, he might not even recall peeing on your couch (a phrase I never expected to write in a money column, but here we are) so the responsibility is on you and your wife to bring it up.
They broke an agreement that you made together and took advantage of you by not contributing at all to the cost of the trip. They should be ashamed of themselves! You have every right to speak to them about this. Remind them that you all agreed on the travel plans and the sharing of costs. They reneged. When you offered to let them ride with you anyway, they should have at least contributed to gas and tolls.